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Construction professionals are at the forefront in reinforcing the soil with the use and application of methods and materials that help increase its bearing capacity, since one of the main causes of building collapse and settlement is soft soil. For this study, a five-story reinforced concrete building was designed using structural software and a soil-structure interaction analysis was performed. Immediate and differential settlements were calculated with the application of loads from the structure. Four reinforcement analysis models were considered: 1) without improvement; 2) with soil replacement; 3) with geogrids; and 4) with geogrids and footing width reduction. The bearing capacity was estimated using data from soil studies and material parameters from quarries near the study area in Portoviejo, Ecuador. An adaptation to the formulas of Meyerhof & Hanna (1978) was applied for the soil substitution alternative, while the formulas of Huang & Meng (1997) were used and applied for the geogrids. The aim of this analysis is to obtain a high bearing capacity value of the soil that leads to savings in foundation material and at the same time to achieve low numbers of settlements that are deduced to the safety of the structure. The results of the reinforcement in relation to the natural soil revealed a considerable increase for the geogrid alternatives compared to soil substitution, and a reduction in settlements. The percentages obtained after analysis and calculations demonstrate the benefits of using geogrids under this type of structure.

Vaccination is a widely used control strategy to prevent Piscirickettsia salmonis causing disease in salmon farming. However, it is not known why all the currently available commercial vaccines generally fail to protect against this pathogenic bacteria. Here, we report, from two different populations, that between-family variation is a strong intrinsic factor that determines vaccine protection for this disease. While in some full-sib families, the protection added by vaccination increased the survival time in 13 days in comparison with their unvaccinated siblings; in other families, there was no added protection by vaccination or even it was slightly negative. Resistance to P. salmonis, measured as days to death, was higher in vaccinated than unvaccinated fish, but only a moderate positive genetic correlation was obtained between these traits. This disputes a previous hypothesis, that stated that both traits were fully controlled by the same genes, and challenges the use of unvaccinated fish as gold standard for evaluating and selecting fish resistant to P. salmonis, particularly if the offspring will be vaccinated. More studies are necessary to evaluate if variation in the host immune response to vaccination could explain the between-family differences in resistance observed in vaccinated fish.

Introduction: Research on stress and dyslexia has mainly focused on chronic and contextual stress caused by the school environment. Our goal was to test individual differences in the hypothalamic-pituitary-adrenal (HPA) axis reactivity of dyslexic and non-dyslexic children and the related emotional manifestations associated with exposure to a psychosocial stressor., Methods: Eighty-one children (11-14 years old; 38 dyslexic) were exposed to the Trier Social Stress Test adapted to children or to a control condition. The salivary cortisol response, anxiety, and mood were measured before and after the stress., Results: Dyslexic children did not show the expected cortisol response, as the highest percentage of children who were non-reactive to stress was found in this group. Cortisol reactivity to stress was related to higher levels of anxiety and lower positive affect in the non-dyslexic children., Conclusion: These results suggest a pattern of hypo-activation of the HPA axis to psychosocial stress in children with dyslexia., (Copyright © 2019. Published by Elsevier GmbH.)

The impact of sex and the menstrual cycle phase on the autonomic response to psychosocial stress remains controversial. This study explored autonomic nervous system activity through salivary alpha-amylase, heart rate, and heart rate variability responses to the Trier Social Stress Test (TSST) in healthy young people. The sample was composed of 25 men, 26 women in the luteal phase, and 25 women in the follicular phase, from 18 to 25 years of age. Participants were exposed to the TSST or a control condition. The results indicate that women in their follicular phase showed a blunted alpha-amylase response to stress compared to men and women in the luteal phase. In addition, men showed higher sympatho-vagal activity in the stress condition compared to the two groups of women. These results confirm that sex and the menstrual cycle phase are potential modulators of autonomic nervous system reactivity to psychosocial stress., (Copyright © 2018 Elsevier B.V. All rights reserved.)

There is information indicating that the variations induced by the menstrual cycle may influence the capacity of young women to respond to stress. The physiological response to stress changes across the stages of the lifespan; however, in spite of the great increase in life expectancy, the way women react after menopause, a period characterized by a dramatic decline in sex hormones, has not been sufficiently studied. The main objective of the study was to examine the capacity to respond to and recover from an acute social stressor in post-menopausal women compared to young women. The second objective was to investigate the consequences of behavior on the self-regulatory systems. We measured behavior, cortisol, and heart rate during a speaking task in front of a committee in sixty-seven women: 36 post-menopausal and 31 pre-menopausal (follicular group n=14; luteal group n=17). No differences in heart rate reactivity between three groups were found. Post-menopausal women showed less cortisol reactivity to stress; they also displayed a higher percentage of Gestures during the speaking task, reflecting a clearer pattern of active coping compared to the young women. In post-menopausal women, behaviors that reflect active coping strategies were related to better autonomic regulation. By contrast, in pre-menopausal women, cortisol changes seemed to be modulated by passive and reactive behaviors such as Submission and Assertion. These results emphasize the importance of considering age and Hormonal Status in coping processes, including reactivity and recovery from stressful situations., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Little is known about age differences in the effects of stress on memory retrieval. Our aim was to perform an in-depth examination of acute psychosocial stress effects on memory retrieval, depending on age and sex. For this purpose, data from 52 older subjects (27 men and 25 women) were reanalyzed along with data from a novel group of 50 young subjects (26 men and 24 women). Participants were exposed to an acute psychosocial stress task (Trier Social Stress Test) or a control task. After the experimental manipulation, the retrieval of positive, negative and neutral pictures learned the previous day was tested. As expected, there was a significant response to the exposure to the stress task, but the older participants had a lower cortisol response to TSST than the younger ones. Stress impaired free recall of emotional (positive and negative) and neutral pictures only in the group of young men. Also in this group, correlation analyses showed a marginally significant association between cortisol and free recall. However, exploratory analyses revealed only a negative relationship between the stress-induced cortisol response and free recall of negative pictures. Moreover, stress impaired recognition memory of positive pictures in all participants, although this effect was not related to the cortisol or alpha-amylase response. These results indicate that both age and sex are critical factors in acute stress effects on specific aspects of long-term memory retrieval of emotional and neutral material. They also point out that more research is needed to better understand their specific role., (Copyright © 2015 Elsevier B.V. All rights reserved.)

A novel electrochemical microcystin-LR (MC-LR) biosensor based on the inhibition of recombinant protein phosphate type 1 (PP1α) is reported in this work. The use of innovative recombinant enzyme led to investigate new commercially available substrate, electrochemically active after their dephosphorylation by PP1α. Only two of selected substrates, 1-naphylphosphate and phosphoparacetamol, showed a good affinity toward PP1α. Kinetic parameters were performed by classical colorimetric assays and revealed that phosphoparacetamol is an excellent synthetic substrate with a Km value of 1.2 mM. The reported biosensor is constructed by entrapment of the enzyme in Polyvinyl Alcohol (azid unit) on Cobalt-Phtalocyanine (CoPC) modified screen printed electrode. Electrocatalytic mediator demonstrated a significant improvement in the electrochemical detection of dephosphorylated substrate. The standard inhibition curve has provided a limit of detection at 0.93 µg/L and a broad dynamic range from 0.93 to 40.32 μg/L for MC-LR, demonstrating the improved analytical performance., (Copyright © 2015 Elsevier B.V. All rights reserved.)

This study explores the influence of pre-learning stress on performance on declarative memory tasks in healthy young adults in relation to sex and menstrual cycle phase. The sample was composed of 119 students (32 men and 87 women) from 18 to 25 years of age. The women were tested in different hormonal stages (30 in follicular phase, 34 in luteal phase, and 23 using oral contraceptives). The participants were exposed to the Trier Social Stress Test (TSST) or a control condition. Afterwards, their memory performance was measured using a standardized memory test (Rey's Auditory Verbal Learning Test). In the control condition, all groups of women recalled more words than men, but these differences disappeared in the group exposed to TSST because men's performance on the memory test improved, but only to the level of women. In addition, our data suggest that in women the relationship between cortisol and memory can be modulated by sex hormone levels, since in luteal women a negative relationship was found between memory performance and peak cortisol level. These results confirm that sex differences need to be considered in the relationship between pre-learning stress and memory performance., (Copyright © 2013 Elsevier Inc. All rights reserved.)